Start Date
4-2020 12:00 AM
Description
Black Cypress Bayou is a primary tributary of Caddo Lake watershed in eastern Texas. The watershed is underlain by Eocene-aged strata from the Wilcox and Claiborne groups, which represent transgressive/regressive shoreline fluctuations that deposited interbedded friable sandstones and mudstones. The Wilcox Group is of special interest because it contains lignite coal, which has a direct link to heavy metals in sediment and natural waters. Caddo Lake has been listed on the Texas Commission on Environmental Quality 303(d) list for impairment due to mercury in edible tissue since 1995 and Black Cypress Bayou has been listed for impaired waters due to elevated copper since 2010.
In July 2019, water and sediment samples from six locations along Black Cypress Bayou were analyzed for metal concentrations including Ca, Fe, Pb, Mg, Mn, Na, Zn, and Hg. Physiochemical parameters of water samples (temperature, pH, and conductivity) were recorded in the field; and later analyzed in the laboratory for cation/metals and anion concentrations. Sediment samples were collected along the stream banks, processed, and digested using EPA method 6010 for trace metal analyses and EPA 7471 for mercury analyses. Zinc and lead concentrations can be seen in Figure 5. Other metal concentrations were not detectable or within normal limits for the environment.
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Geochemical Analyses of Base Metals in Sediments and Stream Water Black Cypress Bayou, Marion County, Texas
Black Cypress Bayou is a primary tributary of Caddo Lake watershed in eastern Texas. The watershed is underlain by Eocene-aged strata from the Wilcox and Claiborne groups, which represent transgressive/regressive shoreline fluctuations that deposited interbedded friable sandstones and mudstones. The Wilcox Group is of special interest because it contains lignite coal, which has a direct link to heavy metals in sediment and natural waters. Caddo Lake has been listed on the Texas Commission on Environmental Quality 303(d) list for impairment due to mercury in edible tissue since 1995 and Black Cypress Bayou has been listed for impaired waters due to elevated copper since 2010.
In July 2019, water and sediment samples from six locations along Black Cypress Bayou were analyzed for metal concentrations including Ca, Fe, Pb, Mg, Mn, Na, Zn, and Hg. Physiochemical parameters of water samples (temperature, pH, and conductivity) were recorded in the field; and later analyzed in the laboratory for cation/metals and anion concentrations. Sediment samples were collected along the stream banks, processed, and digested using EPA method 6010 for trace metal analyses and EPA 7471 for mercury analyses. Zinc and lead concentrations can be seen in Figure 5. Other metal concentrations were not detectable or within normal limits for the environment.
Comments
Faculty Sponsor: Mindy Faulkner (Department of Geology)